Electric motor



July 14, 1942. R. lNrUMrals-HER ETAL ELECTRIC MOTOR Filed May l0, 1939 2 Sheets-Sheet l July 14, 1942.

R. NEUMEISTER ETAL ELECTRIC MOTOR Filed May lO, 1959 2 Sheets-Sheet 2 /5 /SZ ,6K 2/ /7 4 j AC/t INVENTORS.

- Ruoo/f /Veume/Sfer Effe/nz Gross/7ans ATTORNEY.

Patented July 14, 1942 UNITED; STAT Es PATENT orifice ms i f v femorale iviofroitv x l l l Rudolf Neun:eistei","Berlin,y and Heinz (lrcsshans,`

Blankenfelde, near Berlin, Germany, as signors y to Siemens. Apparate Vund, liriaschinen` Geselle, l Schaft mit beschrnkter.Hattungferlin, Ger- .v many, acorporation of 4Germany v .are spatially distributed in such a manner that This invention relates to electric motors, and

, more particularly to an arrangement of'jthe windings, and winding slots, of electric motors.

It is lknown that a rotating magnetic field for' an electric motor may be created by two phase or polyphase4 alternating current'vwhich passes through two or more windings, `the axes of which are angularly disposedrelative to onea'nother in a predetermined manner.'

rangements of this type -arev characterized by great electrical and magnetic'symmetry. However, quite frequently it -is necessary tor create a rotating field through electric impulses, i. ye. by irregularly acting `current or voltage changes.

In electric remote transmission devices, for exv ample, a transmitter rotor canv be adjusted to a givenV angular position which will produce cur- `rent impulses in areceiver to create therein a rotating magnetic field having a-directionwhich causes a. receiver rotor to assume a corresponding position to that of the transmitter rotor. Rotating magnetic fields which are produced by electric impulses and which act in winding arrangements heretofore proposed do notpossess a uniform behavior'in all'phasesnof the ltransmission period. The torques which act upon the receiver rotor vary with the angle of torsion.

' The iron circuit or iron contact, that is the area of iron of the stator adjacent the iron of the rotor, is variable, and the electric and magnetic characteristics of the arrangement are not uniform but subject' to rapid fluctuation. These Rotating field ar- ,1o

19:59, serial No.v 272,902` anuary 22,1937'v lmission system whereby a constant torque is exerted upon the rotor of said receiver as it follows j a transmitter throughv 360.

The above and further objects and novel features will more fully appear from the following detailed description when the same lis read in connection with .the accompanying drawings.v ,It is to be expressly understood, however, that the drawings are for purposes of illustration only and are not intended .as a definition of the limits pose being hadto the appended claims.

characteristicstend to reduce the transmission f accuracy and to disturb the uniformity of the indications. I

, One of the objects of the present invention is to `provide a novel winding arrangement for vthe creation of a uniformrotating field for receivers of an electric remote transmission system by means of electric impulses. g

Another object of the invention is to provide a novel coil arrangementv for an electric motor wherein magnetic losses are reduced to 'a minimum. l f y Y A still further object is toprovide a novel winding for an electric remote transmission system which will increase the accuracy of the reproducy l tion of a transmitted value. y

An additional Objectis to provide la novel winding arrangerne'nt'which enables thecreation of a rotatable iield wherein the fluctuationr of magnetic effects is reduced to a minimum.

Another object .is to provide a. novel winding yarrangement whereiuthe wires of different coils' of circuit connecting togethertwo motors em` In the `drawingsVwherein like reference char.-

acters refer to like parts throughout the several views,

Fig. l is a perspective view of a stator and winding illustrating one embodiment of the invention; f

Fig. 2 is a plan view of an arrangement ofwires in accordance with a second embodiment of the invention;

Fig. 3 is a side elevation of a stator and windings therefor which may be employed in the present invention;

Fig. 4 is a detail sectional view, with parts l brokenv away, of a slotted stator having coils therein arranged in accordance with the invention; Y

Fig. 5 is a development of a Winding which may be employed in the stator of Fig. 3;

Fig. 6 is a development ofthe surface of a rotorhaving slots ,therein arranged in accordance with another embodiment of the invention; Fig-'l is a'development of the surface `of a rotor having slots therein arranged in accordance with `another emobdiment of the invention;

Fig. 8 is a development of an inside surface of the stator shown in Fig. l, illustrating the manner .in which the four` sets of coils are arranged in the slots;

Fig. 9 is a developed view similar to Fig. 8 but shows the manner in which the sets of coils are interconnected to form two windings in twophased' relation; l

Fig. 10 is a. wiring diagram Ashowing one form b'odying the invention; and I Fig. 11 shows .one form of'rotor and rotor winding used `with the stator of Fig. 1.

The `forms of the invention illustrated in the accompanying drawings, by way of example, comprise novel arrangements of the windings and winding slots which may be employed in connection with rotating field receivers for electric remote transmission systems, the receiver having suitable slots in the rotor or stator thereof. Two or more windings are placed insaid slots, each winding having two or more coil turns constituted by one or more turns of Wire. The wire of each coil turn of one winding is in contact along the length thereof, but electrically insulated therefrom, with the wire of each coil turn of the other windings which lies in the same slots.`

This lengthwise contact may be accomplished by either initially twisting the wires together about a feed spool from which the coils are, then wound about a core either by hand or machine.-

or by binding the wires together adjacent one resultant magnetic field M1.

1 of winding II are connected to coils which are another in a parallel relationship. In order to obtain a'uniforrn iron`circuit, the slots of either the stator or the rotor are skewed ror twisted over a substantial proportion of the circumference of the slotted member.-

The windings for the creation of the rotating v field can be arranged either on the rotor or the stator of a transmission system of the above character. It is preferable, however, to arrange the windings upon the stator. In the forms shown, in association with a stator are two windings, the magnetic vectors of which are displaced relative toone another by 90, thus forming a cross-coil system.- From a ytransmitter (not shown) current impulses pass to these windings, which with reference to their intensity or temporal duration are related to one another in the proportion of the sine to the cosine of an angle a which is to be transmitted. The resulting magnetic field formed by the two componentsin the receiver possesses at all times the direction of angle a, and a receiver rotor, which may be constitutedA by a magnetic needle or an electromag-` 'l net, tends to coincide in its position with the direction of said field.

In the form shown in Fig. 1, a stator 9 having eight slots I0, II, I2, I3 and I0', II', I2', I3 is provided with a winding I, the coil turns of which have wires which for the sake of clarity are illustrated with black cross-sectional areas, and a winding II, the coil turns of which have wires of a White cross-sectional area, said wires being suitably. covered with electric insulation. In onder to obtain the greatest possible uniformity of magnetic eiect of the coils of the separate windings, it is necessary that the wires of dif-v ferent coil turns lying in the same slots be spatially distributed to create equal magnetic effects. This is accomplished in this embodiment by twisting the wire of each coil turn of one winding with the wire of other coil turns of other windings which lie inv the same slots. Each winding is distributed equally over the eight slots so that if each coil of each winding is wound from one slot to the opposite slot, thus constituting the angularly separated from those of the winding I by 90, a magnetic field M2, created by the four coils of the former, isdisplaced 90 from M1. The components of theeld Mz are not shown. The fields Mi and Mz combine to form a resultant field 'Ma which acts upon a rotor (not shown) to cause same to assume the direction of field Mr.

Instead of twisting together the wires whichv comprise each coil of the separate windings, it

may be desirable to secure the wires of each coil turn in a parallel relation as shown in Fig. 2, the wires being held adjacent one another bysuitable binding strips 26 .distributed at predetermined intervalsl along the length thereof, or a covering (not shown) for the full length of the wires may be employed. After the wires are so bound, the positioning of the coils ofeach winding may be accomplished as described above. Of course, it

is also possible, to wind the wires of each coil in.

a `parallel relation as shown in Fig. 2, without will, as a rule bedilicult to perform.

Referring nowto Fig. 8, thewires forming the first set of coils I4, I8 are first twisted together as .shown in Fig. 1 or are enclosed in a cover as shown in Fig. 2 and are then wound so that the coils I4, I8 rst enter slot I0 fromvthe top as shown in Fig. 8 yand then enter slot I0' from the bottom and emerges from said slot I0 at the top.

The coils I5, I9 and I6, 20 and I1, 2I are simi-` larly twisted and are wound so that coils I5, I9

are disposed in slots II and II', coils I620 in slots lzend lz', and-'cons l1, 2| in slots I3 and I3 as shown.

Referring now tol Fig. 9, the foursets of coils are interconnected to form the windings I and II as follows: l I

One end of coil-I8 is connected to one end of coil L9 by lead I8a. The other end of coil I8 is connected-to one end of coil 2| by lead 2I a. One end of coil I4 is connected to a terminal lead 2'2 and the other end is connected to one end of coil I5 by lead I4a, the other end of coil I5 being connected to one end of coil I6 by lead I5a.

The other end of coil I6 is connected to one endy (of coil I1 by lead IEa, and the other end of coil'r I1 is connected to a terminal lead 23. Thus winding I compromises the terminal lead 22, coils I4, I5, I8, I1 and terminal lead 23.

A terminal lead 24 is connected to one end of coil 20 and the other end of said coil 20 is conarrangement a full pitch winding, each winding l will contain four coils. For purposes of illustration, each coil is shown as having but one wire, the coils of winding I being constituted by wires I4, I5, I6, I1 and those of winding II being con-` stituted by wires I8, I9, 20, 2I. The wires of the former group, as above mentioned, are twisted with those of the latter group respectively, and the coils of each winding are interconnected in a manner analogous to a connection to be later explained, winding I being provided with ter minals 22, 23 and winding II with terminals 24,

nected to one end of coil 2I by lead 20a, the other end of said coil. 2I being connected to coil I8 by lead 2Ia as previously stated. The remaining end ofcoil I9 is connected to a terminal lead 25. Ac-

cordingly, winding II comprises terminal lead 24,' coils 20, 2I, I8, I9 and terminal lead 25. It will vbe noted that coils I4, I5, I6 and I1 of winding I are respectively displaced`90 with respect to coils 20, 2I, I8 and I9 of winding II.

The connections of the coils lying in the various slots are illustrated in Fig. 3 which shows a stator 21 wound in accordance with' the invention. A plane development of vthe windings with connecting leads is shown in Fig. 5. In Fig. 3

.the ,stator 21 is provided with sixteen -slots 28 to 35, inclusive, and 28 to 35', inclusive. A full 44; however, a current lead-in 45 ty degrees separated from their total effect creating pitch winding,` for exampleI is shown, consequently each two opposing slots, as

resulting rotating field. Itis advisable, to cause 28 and- 25', contain two coils,f'one of whichisa'part of winding land the `naar aparte: 'winding- 1I.- For 'purposes cross-sectionsoL-the-l coils in' .Il

21T are shown .by hatching; f

of illustration, the the slots'of stator however, the e've'n" and 'uniform' distribution of.`

stator ast shown f which togethery or joined in a parallel relation as'above described. In the piane d winding I, and coils 36 to 43', inclusive, of winding II. Coils 36 to 43 are coil'36 and a' current-leadfoi 48 atcoil 43. Ninethe two terminals 45,- 3 are'suitable terminals 41, 48, nected to coils 39'A and velopment of the .windings as shown in Fig. 5 are coils 38. izo-*43, vinclusive,.-of`

- amountsjtodsf. interconnected by leads is provided atrespectively, con- 40', the former terminali A being a current lead-off 'and the latter a lead-in. Coils 36 to 39 Vare successively interconnectedby leads 49,'c`oils 40 to 43' by leads 50, and the two coils 43"an'd 36' by a leadl."

The magnetic vectors-of the coils to. pro-v;

duce a resultant field m1 and the vectors of coils 36' to 43 produce. a resultant iield mzin a man'v ner analogous to that above set forth. When:

it is of course necessaryto correct direction in order to avoida Acondition wherein the magnetic fields making-the winding, place the-wires in the o1' one winding weaken the fieldsl of another winding.

II it is intended to-createla rotating field i means oI` phasedisplaced alternating currents, for example, three phase current,the stator and rotormay befarranged axially. However, if the rotating iield is created by means of current impulses, as in the case tion in the present invention, the impulses by sinusoidal currents in the various coils, then there will occur between the poles of the rotor and stator the phenomenon known as the rest or stop or slot effect. In order to reduce this effect, it has been heretofore proposed to skew or twist the rotor and stator slots relative to one another to the extent cf one half of a slot.

However, in transmitter devices with rotating field receivers of the type herein described, a very intense fourth harmonic error curve occurs in spite of a skewing of the slots to this extent. This is explained by the fact that in connection with normally skewed stators and rotors, the ironcircuit between stator and rotor is too irregular so that the torque which acts in controlling the rotor is not equally strong 1n every angular posirotor slots in such a manner that the most uni-- form and even iron circuit is obtained along the entire circumference of the rotor and stator. Consequently, skewing said slots to the extent of one-half of a slot is insufficient. The skewing should extend over a considerable portion of the stator or rotor circumference so that, if possible, all the slots are employed for the creation of the under consideraference, .1. e..by.120.

the transmitter and.v then thereceiver. .The stator winding I of one motorv the stator orthefother motor.

the slots of the rection o r to skew the same to skewthe slots of the rotor.,

Ir it isessumed that. the rotating' iieid is' drei ference 'thereof will substantially eliminate the abovementioned disadvantage., In Fig. 6 a development fof ,the external surface of'a rotor of' this .character `is shown with the'slots thereof'A i skewedetdthe extent' of one-third 0 1'Y the circiim/'f4 The rotor is provided with l of the 1 slotsl 'therefore n In the slots is arranged a wind#V e ing vtraversed by direct currentancl[whichl pro-{j duces. theV twoA magneticV poles spaced from 'each other by 180.

slight amount in dottedjiines, i. e. by 22.5,

provided 'with two winding'sdi'splaced within spect to each other' 90, so as to result ina foi-ir pole rotor- In Fig. is shown a wiring diagram of one form of circuit;y connecting togetherv two motors type shown'either inFig. 1r or Fig. 3. The rotors or' said motors maybe of having stators 'of the the -type'shown in Fig., ll'. Either motor maybe is connected to the stator winding of the other, motor vandflikewise the winding lI I.of t hestator the winding IIff f of r,one motor is connected to` V The rotorof each motor comprises a single phase winding R and;- 1

the two windings are connected together and then to a source of alternating current represented by the leads AC for energization thereby. If the rotor of one motor is displaced angularly the rotor of the other motor will be displaced the same amount by the reaction between the field of its winding and the resultant eld of the windings I and II of its associated stator, in the same manner as the rotors are displaced in the system shown in the patent to Reichel et al. No. 2,038,059, dated April 21, 1936.

There is thus provided a novel arrangement of the coils, and a novel disposition of the slots for said coils in an electric motor of the above character. More uniform magnetic and electrical effects are obtained, a highly uniform iron circuit between rotor and stator is achieved, and slot or stop effect is substantially eliminated. The coil arrangements are simple and easily executed, and the means for obtaining a uniform iron circuit and for reducing slot effect are easily adapted for large scale production at low cost.

Although only five embodiments of the present invention are illustrated and described in detail, it is to be expressly understood that the same is not limited thereto. For example, the invention has been applied to a rotating field receiver with two windings displaced to the extent of relative to one another, the branch currents or which are in the same relation to each other as the sine and the cosine of an angle which is to be transmitted. However, the inventive idea is applicable wherever the individual windings of stator to extend inthe axial di- I e to aslight extent and It isfalso advisable to skew by a y the slots ofthe stator, ic rI exi-f' ample,yto theextent of one halfaslot as s'howrrv the other motor willbe,l

the receiver, which windings provide the exciting eld, are to be symmetrical with reference to their magnetic effects." It is to be further understood that inthe claims, where mention is madel of a, motor membergfeitl-ie'ra. rotor or a stator is referred to. What is claimed is: l 1. In apparatus of the vclass' described, a. stator member, a rotor member, said stator and rotor members having slots therein, andy two ork more aaseicvs coil turn being'twisted withthe -wire of each of Y the other `coil turns lying in the same slot. y

windings in the slots of one of said'members, 'each f winding comprisinga plurality o f coil turns of Wire/the wire of'eac'h coil turn of one Winding beinginsulated from and secured along the length thee'o'fffwith thev wire.,` of each coil 'turn' of the other v,windingswhitzlili'es in the same'fslots 2.-In apparatus of theclass de'scrlbedlastator 5.v apparatus of the "classdescribedg, Va-stfiiol`J vmember, a rotor member; said-rotor iand stator members havingislots therein-which aregskewed relative to one another by an amount whichr is 'l V I proportional to the circumference of the members,

and two or more' windings inthe slots of one ,of

l said members,`the -wire of each Windingfbeing ins'ulated fromand secured along the length there- 6. In apparatus vof thefclass describedfav motor member having slotsl therein, two or more wndings in said slots,=the-wire'of each winding being Vus of each otherwwindingyand" binding strips for inv contacti'along the "length thereof ywith the wire binding the' wires -in such contact.'

member, ,a 'rotor member, said Amembers having slots-therein, 'and two or more lwindings-in the slots of oneof` said members,'each Winding comprising two ormore coil turns of wire, the wirev of each coilvturn of one winding being'insulated from andtwisted ,withthewire of `each coil of the' otherl .windings which lies in' the same slot.

3. In apparatus of the class described, a stator member, a...roto1, m emberl said stator and rotor K' membershaving slots therein, andtwoor more windings in the slots of one of said members, each winding being constituted by one or more wires, the .wires of one of said windings being twisted with the wires of other ,windings lying in the same slots.

4l. 'Inv apparatus of the class described comprising," in 'combinationlwith a motor member having"A slots therein, two or more windings for creating a-rotary eld, by means of electrical impuises, said`winding's having the magnetic vectors .thereof aiyigularlyfdisposed,v eachwinding comprising` a. plurality ofcoil turns of wire, the wire y(if-'eachA 7; .In apparatus of the class described, a bi" polar vmotor-member having slots therein, the slots` being skewedto the extent of -one-third o fthe circumference of the'me'mber, and two or more windings 'in said slotsfhaving themagnetic vectors thereof `an'gularlsI disposed in a predetermined relation, each winding comprising-a plurality of coil turns fof wire, the Awire oi each coil turn being insulated from and secured alongthe length thereof with thewire of-each lof the ,other coil turns lying inthe same slot. k,

8. In apparatus of the class described, a four- `pole-motor member having slots therein, theislots being .skewed to the extent of 'one-sixth of the circumference-of the member, and two ormore a windings 'in said slots, each winding comprising a plurality of coil turns lof wire, the Wire of each 'coil turn of one winding being insulated from and securedv along the lengthy thereof with the wire of each coil 'turn Vof the other windings which lies inthesameslot. A Y

HEINZl GRossHANs. n 

